Perimeter

ABSTRACT

A perimeter of the present invention including: visual field scanning screen generating means; fixation image displaying and controlling means; visual target scan line parallel setting means; visual target displaying and controlling means; statically displaying and controlling means for a specific time; static display position storing means for a specific time; kinetic display and control starting means for giving rise to another of the visual target kinetically based on the start point of a specific time from the position which the static display position storing means stores; detecting means; detection position storing means; distance storing means; and scanning continuation means.

BACKGROUND OF THE INVENTION

The present invention relates to a perimeter, an operational method of aperimeter, a program for realizing a perimeter, and a computer-readablerecorded medium.

The following are known as previous perimeters: Goldmann perimeter of510 model [1945], 940 model [1967]; Tubinger perimeter [1957]; Octopusperimeter [1976]. (see, for example, the nonpatent literature 1.)

The explanation of previous perimeters: Goldmann perimeter is the firstbrightness perimeter, adopting manual method of simultaneous recording,with 4 to 60 degrees of brightness of the visual target and 6 types ofvisual angle of the visual target, capable of examining visual field ofvisual angle, and with adjustability of its background brightness. Theshortcoming is that it fails to examine the central region within 5degrees;

Tubinger perimeter [1957] is the first practical, static perimeter,capable of examining the kinetic visual field and the visual field ofcolor, flicker, and etc., adopting manual method of simultaneousrecording, with 80 degrees of brightness of the visual target and 100degrees of brightness of the fixation image and 5 kinds of color and 6degrees of background brightness, and capable of examining the centraland eccentric vision. Its shortcoming is in the difficulty ofcontrolling the visual target movement, and of adjusting the visualtarget, fixation image, and background illumination lamp;

Octopus perimeter [1976] is the world's first fully automated, staticperimeter.

-   Nonpatent literature 1: “The latest comprehensive dictionary of    medical science”, Ishiyaku Publishers Inc., 1987, 1990.

There is the high possibility of erroneous responses made by the subjectdue to habituation, etc., because procedures of previous examinationsare very monotonous.

There exists a considerable discrepancy between the chart resulted froma previous visual field examination and the shape of scotoma and blindspot true to the subject, since the shapes of scotoma and blind spotdetected by previous perimeters are very rough.

It is because of relying on previous perimeters that the early detectionof visual defects has been failing.

The aim of the present invention is, therefore, to provide a perimetercapable of reflecting, in much greater detail, the shape of the scotomaand blind spot true to a subject into the image obtained by theexamination.

The aim of the present invention is also to provide a perimeter reducingthe monotony seen in previous examinations of the visual field.

SUMMARY OF THE INVENTION

The aim of the present invention is to provide the perimeter capable ofreflecting, in much greater detail, the shape of the scotoma and blindspot true to a subject into the image obtained by the examination.

The aim of the present invention is also to provide the perimeterreducing the monotony seen in previous examinations of the visual field.

To achieve the above aim,

The invention of claim 1 is a perimeter including:

-   Means for generating, on an output device, a visual field scanning    screen for scanning a visual field of a subject;-   Means for displaying and controlling a fixation image to be fixated    by said subject, during a visual field scanning, on the visual field    scanning screen generated by said visual field scanning screen    generating means;-   Means for setting a visual target scan line to scan a visual target,    parallel on said visual field scanning screen;-   Means for displaying and scanning said visual target on said visual    field scanning screen along the visual target scan line set by said    visual target scan line parallel setting means, in order to scan the    visual field;-   Means, which is included in said visual target displaying and    controlling means, for statically displaying and controlling said    visual target, for a specific time, on said visual target scan line;-   Means for storing, on a memory device, a position of said visual    target statically displayed and controlled for said specific time by    said statically displaying and controlling means;-   Means, which is included in said visual target displaying and    controlling means, for, while said static displaying and controlling    means displays statically said visual target for said specific time,    giving rise to another of said visual target after a predetermined    moment from the start of said specific time at the position which    said static display position storing means stores, and continuing    said kinetic scan by starting kinetic scan from said position along    said visual target scan line until the time point specified based on    the end point of said specific time;-   Means for, via an input device, detecting a time when said kinetic    scan, started by said kinetic display and control starting means, of    said visual target has first been perceived by the subject's visual    field;-   Means for storing, on the memory device, a position of said visual    target at the time of the detection by said detecting means;-   Means, through said detection position storing means, for storing,    on the memory device, a distance from the position of said visual    target displayed and controlled statically for said specific time by    said statically displaying and controlling means, to the position of    said visual target kinetically displayed and controlled at the time    of the detection by said detecting means, as a piece of information    which reflects a function of the visual field extending from the    position of said visual target displayed and controlled statically    for said specific time by said statically displaying and controlling    means, to the position of said visual target kinetically displayed    and controlled at the time of the detection by said detecting means;-   And scanning continuation means for, through said statically    displaying and controlling means, displaying and controlling said    visual target statically on said visual target scan line at the    position of said visual target stored by said detection position    storing means,-   And proceeding from said static display position storing means    onward as above,-   And continuing the similar scan of said visual target scan line by    iterating above procedure along said visual target scan line,-   in order to continue the next scan of said visual target scan line    if the time when said kinetic scan has first been perceived by the    subject's visual field is detected via the input device by said    detecting means;    wherein said specific time being determined based on from the time    of detection, via said input device, of a time when said kinetic    scan, started by said kinetic display and control starting means, of    said visual target has first been perceived by the subject's visual    field, to the time of detection subsequent to said time, via said    input device, of a time when said kinetic scan, started by said    kinetic display and control starting means, of said visual target    has first been perceived by the subject's visual field.

The invention of claim 2 is a program for causing a computer to realizethe function including:

-   Means for generating, on an output device, a visual field scanning    screen for scanning a visual field of a subject;-   Means for displaying and controlling a fixation image to be fixated    by said subject, during a visual field scanning, on the visual field    scanning screen generated by said visual field scanning screen    generating means;-   Means for setting a visual target scan line to scan a visual target,    parallel on said visual field scanning screen;-   Means for displaying and scanning said visual target on said visual    field scanning screen along the visual target scan line set by said    visual target scan line parallel setting means, in order to scan the    visual field;-   Means, which is included in said visual target displaying and    controlling means, for statically displaying and controlling said    visual target, for a specific time, on said visual target scan line;-   Means for storing, on a memory device, a position of said visual    target statically displayed and controlled for said specific time by    said statically displaying and controlling means;-   Means, which is included in said visual target displaying and    controlling means, for, while said static displaying and controlling    means displays statically said visual target for said specific time,    giving rise to another of said visual target after a predetermined    moment from the start of said specific time at the position which    said static display position storing means stores, and continuing    said kinetic scan by starting kinetic scan from said position along    said visual target scan line until the time point specified based on    the end point of said specific time;-   Means for, via an input device, detecting a time when said kinetic    scan, started by said kinetic display and control starting means, of    said visual target has first been perceived by the subject's visual    field;-   Means for storing, on the memory device, a position of said visual    target at the time of the detection by said detecting means;-   Means, through said detection position storing means, for storing,    on the memory device, a distance from the position of said visual    target displayed and controlled statically for said specific time by    said statically displaying and controlling means, to the position of    said visual target kinetically displayed and controlled at the time    of the detection by said detecting means, as a piece of information    which reflects a function of the visual field extending from the    position of said visual target displayed and controlled statically    for said specific time by said statically displaying and controlling    means, to the position of said visual target kinetically displayed    and controlled at the time of the detection by said detecting means;-   And scanning continuation means for, through said statically    displaying and controlling means, displaying and controlling said    visual target statically on said visual target scan line at the    position of said visual target stored by said detection position    storing means,-   And proceeding from said static display position storing means    onward as above,-   And continuing the similar scan of said visual target scan line by    iterating above procedure along said visual target scan line,-   in order to continue the next scan of said visual target scan line    if the time when said kinetic scan has first been perceived by the    subject's visual field is detected via the input device by said    detecting means;    wherein said specific time being determined based on from the time    of detection, via said input device, of a time when said kinetic    scan, started by said kinetic display and control starting means, of    said visual target has first been perceived by the subject's visual    field, to the time of detection subsequent to said time, via said    input device, of a time when said kinetic scan, started by said    kinetic display and control starting means, of said visual target    has first been perceived by the subject's visual field.

In FIG. 1, a visual field mapping rectangle is filled with a green whosebrightness is decreased according to severity of the decline in visualfunction of the corresponding visual field, by a CPU 501.

In FIG. 1, a scotoma 201, a blind spot 203, a connection of scotoma withblind spot 202, etc. are explicitly shown by a cluster of visual fieldmapping rectangles of dark greens.

The perimeter of the present invention can map visual function of thevisual field.

The perimeter of the present invention can map in detail not only thescotoma 201 and blind spot 203, but also portions of visual field wherevisual function slightly declines 204.

In FIG. 1, not only the scotoma 201 and blind spot 203 but also visualfunction of the visual field is mapped.

In FIG. 1, which is an example of the visual field mapping imagegenerated by the perimeter of the present invention,

portions of visual field where visual function slightly declines 204 areexplicitly shown in detail regarding their locations, sizes, shapes,etc., by a cluster of the visual field mapping rectangles filled withdark greens.

The perimeter of the present invention can also map the condition ofvisual function in the vicinity of a fovea 205 of the visual field.

The fovea 205, which has the highest functioning among visual field, isrepresented, in FIG. 1, by a cluster of the visual field mappingrectangles filled with greens of higher brightness.

For the perimeter of the present invention,

-   the CPU 501 forms a visual field mapping rectangle from data    obtained by its scanning of a visual field and carries out an image    processing for the visual field mapping rectangle based on the data,    through which, in the meanwhile,-   the CPU 501 can generate a visual field mapping image proper for    being called scan of visual field, strongly indicating the retinal    structure and so forth.

The perimeter of the present invention may be embodied by a simple setupwithout the need for voluminous equipment such as Goldmann perimeter andthe like.

The perimeter of the present invention can examine the central portionwithin 5 degrees of a visual field.

The perimeter of the present invention reduces the monotony of thevisual field examination accompanied by the existing perimeters, in itsoperational aspect of the visual target display control, etc.

In FIG. 7, a visual field mapping rectangle is filled with a green whosebrightness is increased according to severity of the decline in visualfunction of the corresponding visual field, by a CPU 501.

In FIG. 7, a scotoma 201, a blind spot 203, a connection of scotoma withblind spot 202, etc. are explicitly shown by a cluster of visual fieldmapping rectangles of bright greens.

The perimeter of the present invention can map visual function of thevisual field. In FIG. 7, not only the scotoma 201 and blind spot 203 butalso visual function of the visual field is mapped.

The perimeter of the present invention can also map the condition ofvisual function in the vicinity of a fovea 205 of the visual field.

The fovea 205, which has the highest functioning among visual field, isrepresented, in FIG. 7, by a cluster of the visual field mappingrectangles filled with greens of lower brightness.

For the perimeter of the present invention,

-   the CPU 501 forms a visual field mapping rectangle from data    obtained by its scanning of a visual field and carries out an image    processing for the visual field mapping rectangle based on the data,    through which, in the meanwhile,-   the CPU 501 can generate a visual field mapping image proper for    being called scan of visual field, strongly indicating the retinal    structure and so forth.

The perimeter of the present invention may be embodied by a simple setupwithout the need for voluminous equipment such as Goldmann perimeter andthe like.

The perimeter of the present invention can examine the central portionwithin 5 degrees of a visual field.

The perimeter of the present invention reduces the monotony of thevisual field examination accompanied by the existing perimeters, in itsoperational aspect of the visual target display control, etc.

According to the first invention of a perimeter, a visual field mappingimage, as shown in FIG. 1 and FIG. 7, can be obtained based on the datagenerated from a scanning of a visual field by the perimeter of thepresent invention.

The perimeter of the present invention reduces the monotony of thevisual field examination accompanied by the existing perimeters, in itsoperational aspect of the visual target display control, etc.

The perimeter of the present invention can generate data regardingvisual function of the visual field.

The perimeter of the present invention can also generate data regardingthe condition of visual function in the vicinity of fovea of the visualfield.

The perimeter of the present invention can generate data relating notonly to the scotoma and blind spot but also to regions where visualfunction of the visual field slightly declines.

According to the second invention of a program, a visual field mappingimage, as shown in FIG. 1 and FIG. 7, can be obtained based on the datagenerated from a scanning of a visual field by carrying out the programfor realizing the perimeter of the present invention.

The perimeter of the present invention reduces the monotony of thevisual field examination accompanied by the existing perimeters, in itsoperational aspect of the visual target display control, etc.

The perimeter of the present invention can generate data regardingvisual function of the visual field.

The perimeter of the present invention can also generate data regardingthe condition of visual function in the vicinity of fovea of the visualfield.

The perimeter of the present invention can generate data relating notonly to the scotoma and blind spot but also to regions where visualfunction of the visual field slightly declines.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an image demonstrating an embodiment of the visual fieldmapping image generated by a preferred scanning of the present inventionof the perimeter.

FIG. 2 is a schematic diagram showing a preferred embodiment of thescanning, operation, and visual field mapping aspect of the presentinvention of the perimeter.

FIG. 3 is a diagram showing a preferred embodiment of the system of thepresent invention of the perimeter.

FIG. 4 is a flow chart showing a preferred embodiment of the visualfield scanning and visual field mapping process of the present inventionof the perimeter.

FIG. 5 is a continued flow chart showing a preferred embodiment of thevisual field scanning and visual field mapping process of the presentinvention of the perimeter.

FIG. 6 is a block diagram showing a preferred embodiment of the hardwareconfiguration of the CPU in the present invention of the perimeter.

FIG. 7 is an image demonstrating an embodiment of the visual fieldmapping image generated by a preferred scanning of the present inventionof the perimeter.

FIG. 8 is a schematic diagram showing a preferred embodiment of thescanning and operation aspect of the present invention of the perimeter.

DETAILED DESCRIPTION OF THE INVENTION

The detailed explanation of the present invention of a perimeter, anoperational method of a perimeter, a program for realizing a perimeter,and a computer-readable recorded medium will be disclosed as below whilereferring to the drawings.

Firstly, a setup of the present invention of the perimeter is describedreferring to FIG. 3 and FIG. 6.

FIG. 3 shows an embodiment of the system of the present invention of theperimeter.

FIG. 6 shows an embodiment of the hardware configuration of the CPU 501in the present invention of the perimeter.

FIG. 3 shows a computer system 301 diagrammatically.

The present invention of the perimeter is realized by the computersystem 301 carrying out a program for realizing a perimeter.

As shown in FIG. 3, the computer system 301 realizing an embodiment ofthe present invention of the perimeter includes a main unit 302 that isequipped with a CPU (Central Processing Unit) 501, etc., which will bementioned later, a keyboard 303, (if necessary, a mouse 306), a display304, and a printer 305 (and if necessary, a speaker 307 too).

Next, an embodiment of the hardware configuration of the CPU 501 in thepresent invention of the perimeter is described referring to FIG. 6.

The CPU 501 in the present invention of the perimeter is configuredspecifically including:

-   a microprocessor such as the CPU 501, a RAM (Random Access Memory)    502, a ROM (Read Only Memory) 503, a HDD (Hard Disc Drive) 504, a    keyboard 303, a mouse 306, a display 304, a printer 305, a speaker    307, and a communications interface.

These parts are connected via a bus 505.

-   (The HDD 504 is connected through the input-output interface to the    bus 505.) The keyboard 303 is connected through the input-output    interface to the bus 505, which enables output to the CPU 501 of    input by the keyboard 303.

The display 304 is connected through the input-output interface to thebus 505, which enables output to the display 304 of image data inputfrom the CPU 501. The printer 305 is connected through the input-outputinterface to the bus 505, which enables output by the printer 305 ofinput from the CPU 501.

-   (The speaker 307 is connected through the input-output interface to    the bus 505, which enables output by the speaker 307 of input from    the CPU 501.)-   (The mouse 306 is connected through the input-output interface to    the bus 505, which enables output to the CPU 501 of input through    the mouse 306.)

The CPU 501 carries out operations characteristic of an embodiment ofthe present invention, by loading onto the RAM 502 a program, which isstored in the HDD (Hard Disc Drive) 504, for realizing the presentinvention of a perimeter.

The CPU 501 carries out controls, and kinds of arithmetic processing, ofthe present invention of the perimeter, according to a program forrealizing the present invention of the perimeter.

The CPU 501 controls display processing of the display 304 (an exampleof the output device). (Specifically, the CPU 501, for example,displaying and controlling the fixation image and the visual target, andgenerating the visual field mapping image from the data obtained by thepresent invention of the perimeter.)

The CPU 501 controls the present invention of the perimeter according toinput by the keyboard 303 (an example of the input device).

The CPU 501 can control the printer 305 and the like so as to output thevisual field mapping image, etc. that are generated based on the dataobtained from the perimeter.

(If necessary,

-   the CPU 501 may control the speaker 307 (an example of the output    device) to produce output (for example, according to input by an    input device such as the keyboard 303 or the like, or, for example,    when the scan line is changed in the visual field scanning, or, for    example, when the visual field mapping image is output, or the    like).)-   (The CPU 501 may control the present invention of the perimeter    according to input from the mouse 306 (an example of the input    device).)

The keyboard 303 (and if necessary, the mouse 306) and the display 304are used as user interfaces in the present invention of the perimeter.

The keyboard 303 is used, for example, as a device for input (the inputdevice). (If necessary, the mouse 306 is used as a device for performingvarious kinds of operations of input to the display screen of thedisplay 304.)

The display 304 is a display device (the output device), for example, ofa LCD (Liquid Crystal Display), a CRT (Cathode Ray Tube), or the like,which scans a visual field in accordance with the present invention ofthe perimeter, and displays a visual field mapping image generated bythe present invention of the perimeter.

-   (If necessary, various screens such as an operation screen and a    setting screen may be displayed on the display 304.)

And when the CPU 501 is connected to communications network such as theInternet and a LAN (Local Area Network), the communications interfacecan be equipped with a network adapter such as a LAN card orcommunications equipment such as a modem, in order to establish datacommunication among the network. In such a case, by installing on thenetwork a server storing a program for realizing the present inventionof the perimeter, and configuring the CPU 501 as a client terminal ofthe server, the operation of the present invention of the perimeter canbe carried out by the perimeter.

A program for realizing the present invention of the perimeter can bestored on any computer-readable recording media (storage media).

Examples of such recording media (storage media) are an optical disk, amagneto-optic disk (CD-ROM, DVD-RAM, DVD-ROM, MO, etc.), amagnetic-storage device (hard disk, Floppy Disk™, ZIP, etc.), asemiconductor memory, etc.

Next, the detailed explanation regarding the present invention of aperimeter, operational method of a perimeter, and program for realizinga perimeter will be described while referring to FIG. 2, FIG. 4, FIG. 5and FIG. 8, as below.

FIG. 2 is a schematic diagram showing a preferred embodiment of thescanning, operation, and visual field mapping aspect of the presentinvention of the perimeter.

FIG. 4 and FIG. 5 are flow charts showing a preferred embodiment of thevisual field scanning and visual field mapping process of the presentinvention of the perimeter.

FIG. 8 is a schematic diagram showing a preferred embodiment of thescanning and operation aspect of the present invention of the perimeter.

A coordinate axis 606 in FIG. 8 is for schematic representation of theposition in x axis direction of a visual target which is displayed andcontrolled in a visual field scanning screen 1.

A coordinate axis 607 in FIG. 8 is a time axis for schematicallyrepresenting the lapse of time.

First, referring to FIG. 2 and FIG. 8, an embodiment of the scanning,operation, and visual field mapping aspect of the present invention ofthe perimeter will be described in detail.

A CPU 501 generates a visual field scanning screen 1 on an output device(for example, a display 304).

The CPU 501 displays a fixation image 2 at a predetermined position onthe visual field scanning screen 1 in accordance with a program forrealizing the present invention of the perimeter.

The fixation image 2 is to be fixated by an eye of a subject duringvisual field scanning.

The CPU 501 sets, in the visual field scanning screen 1, a plurality ofscan lines according to the program for realizing the present inventionof the perimeter. For example, the CPU 501 arranges from an upper sideof the screen a visual target scan line 3, a visual target scan line 4,. . . , and a visual target scan line 5 in order, each with apredetermined spacing (for example, in the y direction).

The CPU 501 does not display such scan lines on the visual fieldscanning screen 1, since each of them is set as a path of a visualtarget in the visual field scanning.

-   (Although visual target scan lines are horizontally set in FIG. 1,    they may be set with other directionality.)

The CPU 501 displays first, for example, a visual target 6 statically,at a left side of the visual field scanning screen 1 on the visualtarget scan line 3 in accordance with the program for realizing thepresent invention of the perimeter.

And after a predetermined moment (in this case, the predetermined momentmay be omitted to proceed to the next process), the CPU 501, inaccordance with the program for realizing the present invention of theperimeter, gives rise to another kinetic visual target from the positionof the visual target 6 (while keep displaying the visual target 6statically), and carries out a display control of making it moverightward at a predetermined constant velocity.

If an input made when movement of the kinetic visual target has firstbeen perceived by the subject's visual field (more specifically, aninput made by a momentary press of, for example, the space key of akeyboard 303) is received through an input device (for example, akeyboard 303 and the like), the CPU 501 stops the rightward scanning ofthe kinetic visual target at the position (for example, a position 600in FIG. 8) at that instant (for example, a time point 602 in FIG. 8) ofthe kinetic visual target, for example, at the position of a visualtarget 7.

At that time, the CPU 501 stores the display positions of the visualtarget 6 and the visual target 7, (and if necessary, for example, thedistance between the visual target scan line 3 and visual target scanline 4,) (and if necessary, for example, relative locations of thefixation image 2, visual target 6, and visual target 7,) on a memorydevice (for example, such as a RAM 502, a HDD 504, etc.).

The CPU 501 generates a visual field mapping screen 16 on an outputdevice (for example, the display 304). (The visual field mapping screen16 may be generated on the output device when the CPU 501 generates thevisual field scanning screen 1 on the output device.)

The CPU 501 reads out the display positions of the visual target 6 andvisual target 7 (and if necessary, for example, the distance between thevisual target scan line 3 and visual target scan line 4,) (and ifnecessary, for example, relative locations of the fixation image 2,visual target 6, and visual target 7), which are stored on the memorydevice (for example, such as the RAM 502, the HDD 504, etc.).

The CPU 501 forms and displays a visual field mapping rectangle 18 onthe visual field mapping screen 16, based on the readout positions ofthe visual target 6 and visual target 7 (and if necessary, based, forexample, on the distance between the visual target scan line 3 andvisual target scan line 4,) (and if necessary, based, for example, onrelative locations of the fixation image 2, visual target 6, and visualtarget 7).

The width of the visual field mapping rectangle 18 is formed based onthe display positions of the visual target 6 and the visual target 7, bythe CPU 501.

The height of the visual field mapping rectangle 18 is formed based, forexample, on the distance between the visual target scan line 3 andvisual target scan line 4, by the CPU 501.

The display position of the visual field mapping rectangle 18 on thevisual field mapping screen 16 is determined based on the displaypositions of the visual target 6 and visual target 7 (and if necessary,based, for example, on relative locations of the fixation image 2,visual target 6, and visual target 7), by the CPU 501.

The CPU 501 fills the visual field mapping rectangle 18 with, forexample, a green (another kind of color may be used for the filling), inaccordance with the program for realizing the present invention of theperimeter.

In the filling, the CPU 501 reads out the distance between the visualtarget 6 and visual target 7 which is calculated through an arithmeticunit and stored on the memory device (for example, such as the RAM 502,the HDD 504, etc.), and, carrying out an arithmetic operation by thearithmetic unit, converts the value of the distance into a value forspecifying (according to the value of the distance) the color code of,for example, G in the RGB.

The CPU 501 fills the visual field mapping rectangle 18 with a greenwhose brightness is increased according to length of the distancebetween the visual target 6 and visual target 7. (The brightness may beset decreasing according to the length of the distance.)

As already described, if an input made when movement of the kineticvisual target, which started the kinetic scan from the position of thevisual target 6, has first been perceived by the subject's visual field(more specifically, an input made by a momentary press of, for example,the space key of the keyboard 303) is received through an input device(for example, the keyboard 303 and the like), the CPU 501 stops therightward scanning of the kinetic visual target at the position (forexample, the position 600 in FIG. 8) at that instant (for example, thetime point 602 in FIG. 8) of the kinetic visual target, for example, atthe position of the visual target 7. And, for example, immediately afterthat time point (for example, the time point 602 in FIG. 8), the CPU 501displays the visual target 7 statically.

And after a predetermined moment (for example, a moment from the timepoint 602 to a time point 603 in FIG. 8), the CPU 501, in accordancewith the program for realizing the present invention of the perimeter,gives rise to another kinetic visual target from the position of thevisual target 7 (for example, the position 600 in FIG. 8,) (while keepdisplaying the visual target 7 statically), and carries out a displaycontrol of making it move rightward at a predetermined constant velocity(for example, at the same velocity as the CPU 501 made the kineticvisual target move rightward from the position of the visual target 6 onthe visual field scanning screen 1 at).

After an input made when movement of the kinetic visual target, whichstarted the kinetic scan from the position of the visual target 6, hasfirst been perceived by the subject's visual field (more specifically,an input made by a momentary press of, for example, the space key of thekeyboard 303) is received through an input device (for example, thekeyboard 303 and the like), and after a predetermined moment (forexample, the time point 603 in FIG. 8), the CPU 501 erases the visualtarget 6 displayed until then statically from the visual field scanningscreen 1.

(Alternatively, at the time when an input made when movement of thekinetic visual target, which started the kinetic scan from the positionof the visual target 6, has first been perceived by the subject's visualfield (more specifically, an input made by a momentary press of forexample, the space key of the keyboard 303) is received through an inputdevice (for example, the keyboard 303 and the like) (, for example, atthe time point 602 in FIG. 8), the visual target 6 statically displayeduntil then may be set to be erased from the visual field scanning screen1.)

If an input made when movement of the kinetic visual target, whichstarted the kinetic scan from the position of the visual target 7 (forexample, the position 600 in FIG. 8), has first been perceived by thesubject's visual field (more specifically, an input made by a momentarypress of, for example, the space key of the keyboard 303) is receivedthrough an input device (for example, the keyboard 303 and the like),the CPU 501 stops the rightward scanning of the kinetic visual target atthe position (for example, a position 601 in FIG. 8) at that instant(for example, a time point 604 in FIG. 8) of the kinetic visual target,for example, at the position of the visual target 8.

At that time, the CPU 501 stores the display positions of the visualtarget 7 and the visual target 8, (and if necessary, for example, thedistance between the visual target scan line 3 and visual target scanline 4,) (and if necessary, for example, relative locations of thefixation image 2, visual target 7, and visual target 8,) on a memorydevice (for example, such as a RAM 502, a HDD 504, etc.).

The CPU 501 reads out the display positions of the visual target 7 andvisual target 8 (and if necessary, for example, the distance between thevisual target scan line 3 and visual target scan line 4,) (and ifnecessary, for example, relative locations of the fixation image 2,visual target 7, and visual target 8), which are stored on the memorydevice (for example, such as the RAM 502, the HDD 504, etc.).

The CPU 501 forms and displays a visual field mapping rectangle 19 onthe visual field mapping screen 16, based on the readout positions ofthe visual target 7 and visual target 8 (and if necessary, based, forexample, on the distance between the visual target scan line 3 andvisual target scan line 4,) (and if necessary, based, for example, onrelative locations of the fixation image 2, visual target 7, and visualtarget 8).

The width of the visual field mapping rectangle 19 is formed based onthe display positions of the visual target 7 and the visual target 8, bythe CPU 501.

The height of the visual field mapping rectangle 19 is formed based, forexample, on the distance between the visual target scan line 3 andvisual target scan line 4, by the CPU 501.

The display position of the visual field mapping rectangle 19 on thevisual field mapping screen 16 is determined based on the displaypositions of the visual target 7 and visual target 8 (and if necessary,based, for example, on relative locations of the fixation image 2,visual target 7, and visual target 8), by the CPU 501.

The CPU 501 fills the visual field mapping rectangle 19 with, forexample, a green (another kind of color may be used for the filling), inaccordance with the program for realizing the present invention of theperimeter.

In the filling, the CPU 501 reads out the distance between the visualtarget 7 and visual target 8 which is calculated through an arithmeticunit and stored on the memory device (for example, such as the RAM 502,the HDD 504, etc.), and, carrying out an arithmetic operation by thearithmetic unit, converts the value of the distance into a value forspecifying (according to the value of the distance) the color code of,for example, G in the RGB.

The CPU 501 fills the visual field mapping rectangle 19 with a greenwhose brightness is increased according to length of the distancebetween the visual target 7 and visual target 8. (The brightness may beset decreasing according to the length of the distance.)

As already described, if an input made when movement of the kineticvisual target, which started the kinetic scan from the position of thevisual target 7 (for example, the position 600 in FIG. 8), has firstbeen perceived by the subject's visual field (more specifically, aninput made by a momentary press of, for example, the space key of thekeyboard 303) is received through an input device (for example, thekeyboard 303 and the like), the CPU 501 stops the rightward scanning ofthe kinetic visual target at the position (for example, the position 601in FIG. 8) at that instant (for example, the time point 604 in FIG. 8)of the kinetic visual target, for example, at the position of the visualtarget 8. And, for example, immediately after that time point (forexample, the time point 604 in FIG. 8), the CPU 501 displays the visualtarget 8 statically.

And after a predetermined moment (for example, a moment from the timepoint 604 to a time point 605 in FIG. 8) (, for example, it may be thesame amount of time as the predetermined moment of the time from thestart of the static display of the visual target 7 to (, while keepdisplaying the visual target 7 statically,) the generation of anotherkinetic visual target from the position of the visual target 7) (forexample, the time point 605 in FIG. 8), the CPU 501, in accordance withthe program for realizing the present invention of the perimeter, givesrise to another kinetic visual target from the position of the visualtarget 8 (for example, the position 601 in FIG. 8,) (while keepdisplaying the visual target 8 statically), and carries out a displaycontrol of making it move rightward at a predetermined constant velocity(for example, at the same velocity as the CPU 501 made the kineticvisual target move rightward from the position of the visual target 6at).

After an input made when movement of the kinetic visual target, whichstarted the kinetic scan from the position of the visual target 7 (forexample, the position 600 in FIG. 8), has first been perceived by thesubject's visual field (more specifically, an input made by a momentarypress of, for example, the space key of the keyboard 303) is receivedthrough an input device (for example, the keyboard 303 and the like),and after a predetermined moment (, for example, it may be the sameamount of time as the predetermined moment of the time from the start ofthe static display of the visual target 7 to (, while keep displayingthe visual target 7 statically,) the generation of another kineticvisual target from the position of the visual target 7) (for example,the time point 605 in FIG. 8), the CPU 501 erases the visual target 7displayed until then statically (for example, the visual targetdisplayed at the position 600 in FIG. 8) from the visual field scanningscreen 1.

(Alternatively, at the time when an input made when movement of thekinetic visual target, which started the kinetic scan from the positionof the visual target 7 (, for example, the position 600 in FIG. 8), hasfirst been perceived by the subject's visual field (more specifically,an input made by a momentary press of, for example, the space key of thekeyboard 303) is received through an input device (for example, thekeyboard 303 and the like) (, for example, at the time point 604 in FIG.8), the visual target 7 statically displayed until then (for example,the visual target displayed at the position 600 in FIG. 8) may be set tobe erased from the visual field scanning screen 1.)

By iterating the similar processing, the CPU 501 is now, for example,supposed to carry out a display control of giving rise to anotherkinetic visual target from the position of the visual target 9 (whilekeep displaying the visual target 9 statically), and carries out adisplay control of making it move rightward at a predetermined constantvelocity (for example, at the same velocity as the CPU 501 made thekinetic visual target move rightward from the position of the visualtarget 6 at).

If the kinetic visual target exceeds a right edge on the visual fieldscanning screen 1, a position 3A, the CPU 501 detects that event throughthe arithmetic unit and stores a display position of the visual target9, the position 3A, and, for example, the distance between the visualtarget scan line 3 and visual target scan line 4 (and if necessary, forexample, relative locations of the fixation image 2, the visual target9, and the position 3A), on the memory device (for example, such as theRAM 502, the HDD 504, etc.).

The CPU 501 reads out the display positions of the visual target 9 andposition 3A, and, for example, the distance between the visual targetscan line 3 and visual target scan line 4 (and if necessary, forexample, relative locations of the fixation image 2, visual target 9,and position 3A), which are stored on the memory device (for example,such as the RAM 502, the HDD 504, etc.).

The CPU 501 forms and displays a visual field mapping rectangle 20 onthe visual field mapping screen 16, based on the readout positions ofthe visual target 9 and position 3A, and based, for example, on thedistance between the visual target scan line 3 and visual target scanline 4 (and if necessary, based, for example, on relative locations ofthe fixation image 2, visual target 9, and position 3A).

The width of the visual field mapping rectangle 20 is formed based onthe display positions of the visual target 9 and the position 3A, by theCPU 501.

The height of the visual field mapping rectangle 20 is formed based, forexample, on the distance between the visual target scan line 3 andvisual target scan line 4, by the CPU 501.

The display position of the visual field mapping rectangle 20 on thevisual field mapping screen 16 is determined based on the displaypositions of the visual target 9 and position 3A (and if necessary,based, for example, on relative locations of the fixation image 2,visual target 9, and position 3A), by the CPU 501.

The CPU 501 fills the visual field mapping rectangle 20 with, forexample, a green (another kind of color may be used for the filling), inaccordance with the program for realizing the present invention of theperimeter.

In the filling, the CPU 501 reads out the distance between the visualtarget 9 and position 3A which is calculated through the arithmetic unitand stored on the memory device (for example, such as the RAM 502, theHDD 504, etc.), and, carrying out an arithmetic operation by thearithmetic unit, converts the value of the distance into a value forspecifying (according to the value of the distance) the color code of,for example, G in the RGB.

The CPU 501 fills the visual field mapping rectangle 20 with a greenwhose brightness is increased according to length of the distancebetween the visual target 9 and position 3A. (The brightness may be setdecreasing according to the length of the distance.)

As already described, if the visual target, starting rightward kineticmovement from the position of the visual target 9, exceeds the rightedge on the visual field scanning screen 1, the position 3A, the CPU 501detects that event through the arithmetic unit and, in accordance withthe program for realizing the present invention of the perimeter,switches the scan line to a visual target scan line 4 and (if necessary,after waiting a predetermined moment) displays a visual target 10, at aleft side of the visual field scanning screen 1 on the visual targetscan line 4, for a predetermined moment (, for example, it may be thesame amount of time as the predetermined moment of the time from thestart of the static display of the visual target 7 to (, while keepdisplaying the visual target 7 statically,) the generation of anotherkinetic visual target from the position of the visual target 7), andthen, the CPU 501, in accordance with the program for realizing thepresent invention of the perimeter, gives rise to another kinetic visualtarget from the position of the visual target 10 (while keep displayingthe visual target 10 statically), and carries out a display control ofmaking it move rightward at a predetermined constant velocity (forexample, at the same velocity as the CPU 501 made the kinetic visualtarget move rightward from the position of the visual target 6 at).

After an input made when movement of the kinetic visual target, whichstarted the kinetic scan from the position of the visual target 10, hasfirst been perceived by the subject's visual field (more specifically,an input made by a momentary press of, for example, the space key of thekeyboard 303) is received through an input device (for example, thekeyboard 303 and the like), and after a predetermined moment (, forexample, it may be the same amount of time as the predetermined momentof the time from the start of the static display of the visual target 7to (, while keep displaying the visual target 7 statically,) thegeneration of another kinetic visual target from the position of thevisual target 7), the CPU 501 erases the visual target 10 displayeduntil then statically from the visual field scanning screen 1.

(Alternatively, at the time when an input made when movement of thekinetic visual target, which started the kinetic scan from the positionof the visual target 10, has first been perceived by the subject'svisual field (more specifically, an input made by a momentary press of,for example, the space key of the keyboard 303) is received through aninput device (for example, the keyboard 303 and the like), the visualtarget 10 displayed until then statically may be set to be erased fromthe visual field scanning screen 1.)

If an input made when movement of the kinetic visual target, whichstarted the kinetic scan from the position of the visual target 10, hasfirst been perceived by the subject's visual field (more specifically,an input made by a momentary press of, for example, the space key of thekeyboard 303) is received through an input device (for example, thekeyboard 303 and the like), the CPU 501 stops the rightward scanning ofthe kinetic visual target at the position at that instant of the kineticvisual target, for example, at the position of the visual target 11.

At that time, the CPU 501 stores the display positions of the visualtarget 10 and the visual target 11, and, for example, the distancebetween the visual target scan line 3 and visual target scan line 4(i.e., for example, the distance between the visual target scan linecurrently under scanning and its adjacent visual target scan linealready scanned), (and if necessary, for example, relative locations ofthe fixation image 2, visual target 10, and visual target 11,) on amemory device (for example, such as a RAM 502, a HDD 504, etc.).

The CPU 501 reads out the display positions of the visual target 10 andvisual target 11 and, for example, the distance between the visualtarget scan line 3 and visual target scan line 4 (i.e., for example, thedistance between the visual target scan line currently under scanningand its adjacent visual target scan line already scanned,) (and ifnecessary, for example, relative locations of the fixation image 2,visual target 10, and visual target 11), which are stored on the memorydevice (for example, such as the RAM 502, the HDD 504, etc.).

The CPU 501 forms and displays a visual field mapping rectangle 21 onthe visual field mapping screen 16, based on the readout positions ofthe visual target 10 and visual target 11, and based, for example, onthe distance between the visual target scan line 3 and visual targetscan line 4 (i.e., for example, the distance between the visual targetscan line currently under scanning and its adjacent visual target scanline already scanned) (and if necessary, based, for example, on relativelocations of the fixation image 2, visual target 10, and visual target11).

The width of the visual field mapping rectangle 21 is formed based onthe display positions of the visual target 10 and the visual target 11,by the CPU 501.

The height of the visual field mapping rectangle 21 is formed based, forexample, on the distance between the visual target scan line 3 andvisual target scan line 4 (i.e., for example, the distance between thevisual target scan line currently under scanning and its adjacent visualtarget scan line already scanned), by the CPU 501.

The display position of the visual field mapping rectangle 21 on thevisual field mapping screen 16 is determined based on the displaypositions of the visual target 10 and visual target 11 (and ifnecessary, based, for example, on relative locations of the fixationimage 2, visual target 10, and visual target 11), by the CPU 501.

The CPU 501 fills the visual field mapping rectangle 21 with, forexample, a green (another kind of color may be used for the filling), inaccordance with the program for realizing the present invention of theperimeter.

In the filling, the CPU 501 reads out the distance between the visualtarget 10 and visual target 11 which is calculated through an arithmeticunit and stored on the memory device (for example, such as the RAM 502,the HDD 504, etc.), and, carrying out an arithmetic operation by thearithmetic unit, converts the value of the distance into a value forspecifying (according to the value of the distance) the color code of,for example, G in the RGB.

The CPU 501 fills the visual field mapping rectangle 21 with a greenwhose brightness is increased according to length of the distancebetween the visual target 10 and visual target 11. (The brightness maybe set decreasing according to the length of the distance.)

As already described, if an input made when movement of the kineticvisual target, which started the kinetic scan from the position of thevisual target 10, has first been perceived by the subject's visual field(more specifically, an input made by a momentary press of, for example,the space key of the keyboard 303) is received through an input device(for example, the keyboard 303 and the like), the CPU 501 stops therightward scanning of the kinetic visual target at the position at thatinstant of the kinetic visual target, for example, at the position ofthe visual target 11. And, for example, immediately after that timepoint, the CPU 501 displays the visual target 11 statically.

And after a predetermined moment (, for example, it may be the sameamount of time as the predetermined moment of the time from the start ofthe static display of the visual target 7 to (, while keep displayingthe visual target 7 statically,) the generation of another kineticvisual target from the position of the visual target 7), the CPU 501, inaccordance with the program for realizing the present invention of theperimeter, gives rise to another kinetic visual target from the positionof the visual target 11 (while keep displaying the visual target 11statically), and carries out a display control of making it moverightward at a predetermined constant velocity (for example, at the samevelocity as the CPU 501 made the kinetic visual target move rightwardfrom the position of the visual target 6 at).

After an input made when movement of the kinetic visual target, whichstarted the kinetic scan from the position of the visual target 10, hasfirst been perceived by the subject's visual field (more specifically,an input made by a momentary press of, for example, the space key of thekeyboard 303) is received through an input device (for example, thekeyboard 303 and the like), and after a predetermined moment (, forexample, it may be the same amount of time as the predetermined momentof the time from the start of the static display of the visual target 7to (, while keep displaying the visual target 7 statically,) thegeneration of another kinetic visual target from the position of thevisual target 7), the CPU 501 erases the visual target 10 displayedstatically until then from the visual field scanning screen 1.

(Alternatively, at the time when an input made when movement of thekinetic visual target, which started the kinetic scan from the positionof the visual target 10, has first been perceived by the subject'svisual field (more specifically, an input made by a momentary press of,for example, the space key of the keyboard 303) is received through aninput device (for example, the keyboard 303 and the like), the visualtarget 10 statically displayed until then may be set to be erased fromthe visual field scanning screen 1.)

If an input made when movement of the kinetic visual target, whichstarted the kinetic scan from the position of the visual target 11, hasfirst been perceived by the subject's visual field (more specifically,an input made by a momentary press of, for example, the space key of thekeyboard 303) is received through an input device (for example, thekeyboard 303 and the like), the CPU 501 stops the rightward scanning ofthe kinetic visual target at the position at that instant of the kineticvisual target, for example, at the position of the visual target 12.

At that time, the CPU 501 stores the display positions of the visualtarget 11 and the visual target 12, and, for example, the distancebetween the visual target scan line 3 and visual target scan line 4(i.e., for example, the distance between the visual target scan linecurrently under scanning and its adjacent visual target scan linealready scanned), (and if necessary, for example, relative locations ofthe fixation image 2, visual target 11, and visual target 12,) on amemory device (for example, such as a RAM 502, a HDD 504, etc.).

The CPU 501 reads out the display positions of the visual target 11 andvisual target 12 and, for example, the distance between the visualtarget scan line 3 and visual target scan line 4 (i.e., for example, thedistance between the visual target scan line currently under scanningand its adjacent visual target scan line already scanned,) (and ifnecessary, for example, relative locations of the fixation image 2,visual target 11, and visual target 12), which are stored on the memorydevice (for example, such as the RAM 502, the HDD 504, etc.).

The CPU 501 forms and displays a visual field mapping rectangle 22 onthe visual field mapping screen 16, based on the readout positions ofthe visual target 11 and visual target 12, and based, for example, onthe distance between the visual target scan line 3 and visual targetscan line 4 (i.e., for example, the distance between the visual targetscan line currently under scanning and its adjacent visual target scanline already scanned) (and if necessary, based, for example, on relativelocations of the fixation image 2, visual target 11, and visual target12).

The width of the visual field mapping rectangle 22 is formed based onthe display positions of the visual target 11 and the visual target 12,by the CPU 501.

The height of the visual field mapping rectangle 22 is formed based, forexample, on the distance between the visual target scan line 3 andvisual target scan line 4 (i.e., for example, the distance between thevisual target scan line currently under scanning and its adjacent visualtarget scan line already scanned), by the CPU 501.

The display position of the visual field mapping rectangle 22 on thevisual field mapping screen 16 is determined based on the displaypositions of the visual target 11 and visual target 12 (and ifnecessary, based, for example, on relative locations of the fixationimage 2, visual target 11, and visual target 12), by the CPU 501.

The CPU 501 fills the visual field mapping rectangle 22 with, forexample, a green (another kind of color may be used for the filling), inaccordance with the program for realizing the present invention of theperimeter.

In the filling, the CPU 501 reads out the distance between the visualtarget 11 and visual target 12 which is calculated through an arithmeticunit and stored on the memory device (for example, such as the RAM 502,the HDD 504, etc.), and, carrying out an arithmetic operation by thearithmetic unit, converts the value of the distance into a value forspecifying (according to the value of the distance) the color code of,for example, G in the RGB.

The CPU 501 fills the visual field mapping rectangle 22 with a greenwhose brightness is increased according to length of the distancebetween the visual target 11 and visual target 12. (The brightness maybe set decreasing according to the length of the distance.)

As already described, if an input made when movement of the kineticvisual target, which started the kinetic scan from the position of thevisual target 11, has first been perceived by the subject's visual field(more specifically, an input made by a momentary press of, for example,the space key of the keyboard 303) is received through an input device(for example, the keyboard 303 and the like), the CPU 501 stops therightward scanning of the kinetic visual target at the position at thatinstant of the kinetic visual target, for example, at the position ofthe visual target 12. And, for example, immediately after that timepoint, the CPU 501 displays the visual target 12 statically.

And after a predetermined moment (, for example, it may be the sameamount of time as the predetermined moment of the time from the start ofthe static display of the visual target 7 to (, while keep displayingthe visual target 7 statically,) the generation of another kineticvisual target from the position of the visual target 7), the CPU 501, inaccordance with the program for realizing the present invention of theperimeter, gives rise to another kinetic visual target from the positionof the visual target 12 (while keep displaying the visual target 12statically), and carries out a display control of making it moverightward at a predetermined constant velocity (for example, at the samevelocity as the CPU 501 made the kinetic visual target move rightwardfrom the position of the visual target 6 at).

After an input made when movement of the kinetic visual target, whichstarted the kinetic scan from the position of the visual target 11, hasfirst been perceived by the subject's visual field (more specifically,an input made by a momentary press of, for example, the space key of thekeyboard 303) is received through an input device (for example, thekeyboard 303 and the like), and after a predetermined moment (, forexample, it may be the same amount of time as the predetermined momentof the time from the start of the static display of the visual target 7to (, while keep displaying the visual target 7 statically,) thegeneration of another kinetic visual target from the position of thevisual target 7), the CPU 501 erases the visual target 11 displayedstatically until then from the visual field scanning screen 1.

(Alternatively, at the time when an input made when movement of thekinetic visual target, which started the kinetic scan from the positionof the visual target 11, has first been perceived by the subject'svisual field (more specifically, an input made by a momentary press of,for example, the space key of the keyboard 303) is received through aninput device (for example, the keyboard 303 and the like), the visualtarget 11 statically displayed until then may be set to be erased fromthe visual field scanning screen 1.)

By iterating the similar processing, the CPU 501 is now, for example,supposed to carry out a display control of giving rise to anotherkinetic visual target from the position of the visual target 13 (whilekeep displaying the visual target 13 statically), and carries out adisplay control of making it move rightward at a predetermined constantvelocity (for example, at the same velocity as the CPU 501 made thekinetic visual target move rightward from the position of the visualtarget 6 at).

If the kinetic visual target exceeds a right edge on the visual fieldscanning screen 1, a position 4A, the CPU 501 detects that event throughthe arithmetic unit and stores a display position of the visual target13, the position 4A, and, for example, the distance between the visualtarget scan line 3 and visual target scan line 4 (i.e., for example, thedistance between the visual target scan line currently under scanningand its adjacent visual target scan line already scanned) (and ifnecessary, for example, relative locations of the fixation image 2, thevisual target 13, and the position 4A), on the memory device (forexample, such as the RAM 502, the HDD 504, etc.).

The CPU 501 reads out the display positions of the visual target 13 andposition 4A, and, for example, the distance between the visual targetscan line 3 and visual target scan line 4 (i.e., for example, thedistance between the visual target scan line currently under scanningand its adjacent visual target scan line already scanned) (and ifnecessary, for example, relative locations of the fixation image 2,visual target 13, and position 4A), which are stored on the memorydevice (for example, such as the RAM 502, the HDD 504, etc.).

The CPU 501 forms and displays a visual field mapping rectangle 23 onthe visual field mapping screen 16, based on the readout positions ofthe visual target 13 and position 4A, and based, for example, on thedistance between the visual target scan line 3 and visual target scanline 4 (i.e., for example, the distance between the visual target scanline currently under scanning and its adjacent visual target scan linealready scanned) (and if necessary, based, for example, on relativelocations of the fixation image 2, visual target 13, and position 4A).

The width of the visual field mapping rectangle 23 is formed based onthe display positions of the visual target 13 and the position 4A, bythe CPU 501.

The height of the visual field mapping rectangle 23 is formed based, forexample, on the distance between the visual target scan line 3 andvisual target scan line 4 (i.e., for example, the distance between thevisual target scan line currently under scanning and its adjacent visualtarget scan line already scanned), by the CPU 501.

The display position of the visual field mapping rectangle 23 on thevisual field mapping screen 16 is determined based on the displaypositions of the visual target 13 and position 4A (and if necessary,based, for example, on relative locations of the fixation image 2,visual target 13, and position 4A), by the CPU 501.

The CPU 501 fills the visual field mapping rectangle 23 with, forexample, a green (another kind of color may be used for the filling), inaccordance with the program for realizing the present invention of theperimeter.

In the filling, the CPU 501 reads out the distance between the visualtarget 13 and position 4A which is calculated through the arithmeticunit and stored on the memory device (for example, such as the RAM 502,the HDD 504, etc.), and, carrying out an arithmetic operation by thearithmetic unit, converts the value of the distance into a value forspecifying (according to the value of the distance) the color code of,for example, G in the RGB.

The CPU 501 fills the visual field mapping rectangle 23 with a greenwhose brightness is increased according to length of the distancebetween the visual target 13 and position 4A. (The brightness may be setdecreasing according to the length of the distance.)

By iterating the similar processing, the CPU 501 is now, for example,supposed to carry out a display control of giving rise to anotherkinetic visual target from the position of the visual target 14 (whilekeep displaying the visual target 14 statically), and carries out adisplay control of making it move rightward at a predetermined constantvelocity (for example, at the same velocity as the CPU 501 made thekinetic visual target move rightward from the position of the visualtarget 6 at).

If the kinetic visual target exceeds a right edge on the visual fieldscanning screen 1, a position 14A, the CPU 501 detects that eventthrough the arithmetic unit and stores a display position of the visualtarget 14, the position 14A, and, for example, the distance between thevisual target scan line 3 and visual target scan line 4 (i.e., forexample, the distance between the visual target scan line currentlyunder scanning and its adjacent visual target scan line already scanned)(and if necessary, for example, relative locations of the fixation image2, the visual target 14, and the position 14A), on the memory device(for example, such as the RAM 502, the HDD 504, etc.).

The CPU 501 reads out the display positions of the visual target 14 andposition 14A, and, for example, the distance between the visual targetscan line 3 and visual target scan line 4 (i.e., for example, thedistance between the visual target scan line currently under scanningand its adjacent visual target scan line already scanned) (and ifnecessary, for example, relative locations of the fixation image 2,visual target 14, and position 14A), which are stored on the memorydevice (for example, such as the RAM 502, the HDD 504, etc.).

The CPU 501 forms and displays a visual field mapping rectangle 24 onthe visual field mapping screen 16, based on the readout positions ofthe visual target 14 and position 14A, and based, for example, on thedistance between the visual target scan line 3 and visual target scanline 4 (i.e., for example, the distance between the visual target scanline currently under scanning and its adjacent visual target scan linealready scanned) (and if necessary, based, for example, on relativelocations of the fixation image 2, visual target 14, and position 14A).

The width of the visual field mapping rectangle 24 is formed based onthe display positions of the visual target 14 and the position 14A, bythe CPU 501.

The height of the visual field mapping rectangle 24 is formed based, forexample, on the distance between the visual target scan line 3 andvisual target scan line 4 (i.e., for example, the distance between thevisual target scan line currently under scanning and its adjacent visualtarget scan line already scanned), by the CPU 501.

The display position of the visual field mapping rectangle 24 on thevisual field mapping screen 16 is determined based on the displaypositions of the visual target 14 and position 14A (and if necessary,based, for example, on relative locations of the fixation image 2,visual target 14, and position 14A), by the CPU 501.

The CPU 501 fills the visual field mapping rectangle 24 with, forexample, a green (another kind of color may be used for the filling), inaccordance with the program for realizing the present invention of theperimeter.

In the filling, the CPU 501 reads out the distance between the visualtarget 14 and position 14A which is calculated through the arithmeticunit and stored on the memory device (for example, such as the RAM 502,the HDD 504, etc.), and, carrying out an arithmetic operation by thearithmetic unit, converts the value of the distance into a value forspecifying (according to the value of the distance) the color code of,for example, G in the RGB.

The CPU 501 fills the visual field mapping rectangle 24 with a greenwhose brightness is increased according to length of the distancebetween the visual target 14 and position 14A. (The brightness may beset decreasing according to the length of the distance.)

(In order to clarify the positions of the scotoma 201 and blind spot 203shown in the visual field mapping screen 16 in relation to the displayposition of the fixation image 2 on the visual field scanning screen 1,)

The position on the visual field mapping screen 16, which corresponds tothe display position of the fixation image 2 on the visual fieldscanning screen 1, may be explicitly shown by a fixation image on thevisual field mapping screen 17 in the visual field mapping screen 16.

A cluster of visual field mapping rectangles 15, which is to begenerated as a result of a visual field scanning, is shown as areference to the precise positional representation in the visual fieldscanning screen 1.

A cluster of visual field mapping rectangles 25, which is to begenerated as a result of a visual field scanning, is shown as areference to the precise positional representation in the visual fieldmapping screen 16.

Regarding a visual field scanning and visual field mapping processcarried out by the CPU 501 in accordance with a program for realizingthe present invention of the perimeter, the detailed explanation will bedisclosed as below while referring to FIG. 4 and FIG. 5.

FIG. 4 and FIG. 5 are flow charts showing a visual field scanning andvisual field mapping process to be carried out by a computer shown inFIG. 6.

At the step of S2 of the visual field scanning and visual field mappingprocess, a CPU 501 generates an ID0 window for a visual field scanningscreen 1, on an output device (for example, a display 304).

The CPU 501 sets its width of 600 dots in the x direction and its heightof 460 dots in the y direction.

Hereinafter, the positions are described, in explanation of the visualfield scanning screen 1, assuming that the position of the upper leftcorner of the visual field scanning screen 1 shall be at x coordinate of0 dot and y coordinate of 0 dot and that an x coordinate axis shall begenerated rightward from the upper left corner of the visual fieldscanning screen 1 and a y coordinate axis shall be generated downwardfrom the upper left corner of the visual field scanning screen 1.

At the step of S3, the CPU 501 generates an ID2 window for a visualfield mapping screen 16, on an output device (for example, a display304).

The CPU 501 sets its width of 600 dots in the x direction and its heightof 460 dots in the y direction.

Hereinafter, in the explanation of the visual field mapping screen 16,positions are described assuming that the position of the upper leftcorner of the visual field mapping screen 16 shall be at x coordinate of0 dot and y coordinate of 0 dot and that an x coordinate axis shall begenerated rightward from the upper left corner of the visual fieldmapping screen 16 and a y coordinate axis shall be generated downwardfrom the upper left corner of the visual field mapping screen 16.

At the step of S4, the CPU 501 initializes the values of a variablecounb and a variable counbv to be 0. (For example, a variable counbv isassociated with the position in the y direction of a visual target scanline, and 20+counbv designate the y coordinate of a visual target scanline as, for example, at S12 and S13.) (By initializing the value of thevariable counbv at 0, the position of a visual target scan line is setat an initial position.)

At the step of S5, the CPU 501 initializes the value of a variablefirstz at 0. (A value of the variable firstz is a display position of avisual target that is stored, through the static display positionstoring means, on the memory device, equaling to the x coordinate of aleft side of a visual field mapping rectangle (for example, each ofvisual field mapping rectangles 18, 19, 20, 21, 22, 23, and 24)generated at S20.)

At the step of S6, the CPU 501 initializes the value of a variablexcoordinatez at 0.

-   (Forming a part of a scanning continuation means of the same scan    line.)-   (Forming a part of a scanning switching means to the next scan    line.)

At the step of S7, the CPU 501, for example, interrupts the running ofthe program for a predetermined moment to display the visual targetstatically.

(Relating to the designation of the time period from the time point 604to the time point 605 in the case where a visual target is staticallydisplayed and controlled at the position 600 in FIG. 8.)

-   (Forming a part of a statically displaying and controlling means.)-   (Forming a part of a scanning continuation means of the same scan    line.)-   (Possibly forming a part of a scanning switching means to the next    scan line.)

At the step of S8, the CPU 501 interrupts the running of the program fora predetermined moment, in terms of the (iterative) processing of theprogram.

At the step of S9, the CPU 501 initializes an input receiving means.

At the step of S10, the CPU 501 sets a background color of the visualfield scanning screen 1.

At the step of S10, the CPU 501 fills the visual field scanning screen 1with the background color.

At the step of S11, the CPU 501 sets a color, size, and shape for afixation image, and displays a fixation image 2, for example, at xcoordinate of 300-2 and y coordinate of 200+30 (unit of dot) on thevisual field scanning screen 1.

At the step of S12, the CPU 501 sets a color, size, and shape for avisual target.

The CPU 501, carrying out an arithmetic operation by the arithmeticunit, displays a visual target, for example, at x coordinate of firstzdots and y coordinate of 20+counbv dots on the visual field scanningscreen 1.

-   (Forming a part of a visual target scan line setting means.)-   (Forming a part of a statically displaying and controlling means.)

At the step of S13, the CPU 501 sets a color, size, and shape for avisual target.

The CPU 501, carrying out an arithmetic operation by the arithmeticunit, displays a visual target, for example, at x coordinate offirstz+xcoordinatez dots and y coordinate of 20+counbv dots on thevisual field scanning screen 1.

-   (Forming a part of a visual target scan line setting means.)-   (Forming a part of a kinetic display and control starting means.)

At the step of S14, the CPU 501 carries out a computation offirstz+xcoordinatez through an arithmetic unit, the result of which issubstituted into a variable secondz and stored on a memory device (forexample, such as a RAM 502, a HDD 504, etc.).

-   (The variable secondz forms a part of a detection position storing    means if at S21 and secondz>=600 does not hold.)-   (If a visual target exceeds a right edge of the visual field    scanning screen 1 and secondz>=600 is satisfied, the detection    position storing means may store, in a variable secondz, the x    coordinate of the right edge of the visual field scanning screen 1    in substitution for a position of a visual target at the time of the    detection by a detecting means, as at S16 and S20.)-   (At S20, the variable secondz forms a part of a visual field mapping    rectangle forming means, equaling to the x coordinate of a right    side of a visual field mapping rectangle (for example, each of    visual field mapping rectangles 18, 19, 20, 21, 22, 23, and 24)    generated at S20.)-   (At S22, the variable secondz forms a part of a scanning switching    means to the next scan line.)

At the step of S15, the CPU 501 increments the value of xcoordinatez by,for example, one and stores the result on a memory device (for example,such as a RAM 502, a HDD 504, etc.).

Such an increment is set so as to cause a visual target to take on akinetic characteristic through the CPU 501 (the value of the incrementmay be set at another value).

-   (Forming a part of a kinetic display and control starting means.)-   (The variable xcoordinatez is a distance storing means. (but if a    visual target exceeds a right edge of the visual field scanning    screen 1 and secondz>=600 is satisfied, a distance from the position    of the right edge of the visual field scanning screen 1 to a    starting position of the kinetic display control of the visual    target just before its reaching the right edge, may be set to be    stored in a variable xcoordinatez, as at S16 and S17.))-   (And a value stored in a variable xcoordinatez is the value    representing the length in width of a visual field mapping rectangle    generated at S20, and converted, by the arithmetic unit at S17 and    S18, into a numeric value for designating a color with which the    visual field mapping rectangle is filled.)-   (If necessary, a color other than above mentioned may be designated    for visual field mapping rectangles adjacently generated to both    ends of a scan line.)

At the step of S16, a judgement on if “an input regarding a perceptionof motion of the visual target has been received via an input device” or“secondz>=600 is satisfied”, is made by the CPU 501.

-   If neither holds, the CPU 501 goes back to S8 and continues carrying    out the process to give rise to the visual target that is statically    displayed and controlled and the visual target that is kinetically    displayed and controlled, on the visual field scanning screen 1.-   (Forming a part of a statically displaying and controlling means.)-   (Forming a part of a kinetic display and control starting means.)

In the judgement at the step of S16 on if “an input regarding aperception of motion of the visual target has been received via an inputdevice” or “secondz>=600 is satisfied”, when the CPU 501 judges thateither or both hold, the CPU 501 moves on to S17.

-   (Forming a part of a detecting means.)-   (Forming a part of a scanning switching means to the next scan    line.)

At the step of S17, the CPU 501 carries out a computation of5*xcoordinatez through an arithmetic unit, substituting the result intoa variable colorz, which is stored on a memory device (for example, suchas a RAM 502, a HDD 504, etc.).

-   (Forming a part of a visual field mapping rectangle image processing    means.)

At the step of S18, the value of a variable colorz stored on the memorydevice (for example, such as the RAM 502, the HDD 504, etc.) is read outby the CPU 501, and a judgement whether colorz>=255, is made through anarithmetic unit by the CPU 501.

-   At the step of S18, the CPU 501 moves to S20 and continues the    processing if the CPU 501 judges that colorz>=255 does not hold.-   (Forming a part of a visual field mapping rectangle image processing    means.)

When at the step of S18 the CPU 501 judges that colorz>=255 holds, theCPU 501 updates, at S19, the value of colorz with 255, stores that valuein a memory device (for example, such as a RAM 502, a HDD 504, etc.),and moves on to S20, continuing the processing.

At the step of S20, the CPU 501 generates a visual field mappingrectangle (for example, any one of visual field mapping rectangles 18,19, 20, 21, 22, 23, and 24) on the visual field mapping screen ID2.

-   The CPU 501 sets the position of the upper left point of the    rectangle (for example, the one of visual field mapping rectangles    18, 19, 20, 21, 22, 23, and 24) at (firstz, 20+counbv), and sets the    position of the lower right point of the rectangle at (secondz,    20+counbv+20).-   (Forming a part of a visual field mapping rectangle forming means.)-   (The “+20” in the 20+counbv+20 of the y coordinate at the lower    right corner set a height of a visual field mapping rectangle, and    the “20” is, for example, set in reference to the amount of an    increment made to counbv at S24, that is, an interval between    adjacent visual target scan lines.)-   The CPU 501 fills the visual field mapping rectangle with a color    whose brightness of R, G, B is, for example, 0, colorz, 6,    respectively.-   (Forming a part of a visual field mapping rectangle image processing    means.)

At the step of S21, the CPU 501 updates the content of a variable firstzwith the content stored in a variable secondz, and stores that value ona memory device (for example, such as a RAM 502, a HDD 504, etc.).

-   (The variable secondz forms a part of a detection position storing    means if “at S21” and “secondz>=600 does not hold.”)-   (The rewrote content of a variable firstz forms a part of a    statically displaying and controlling means if “at S21” and    “secondz>=600 does not hold.”)-   (Forming a part of a scanning continuation means of the same scan    line if “at S21” and “secondz>=600 does not hold.”)

At the step of S22, the CPU 501 judges, via an arithmetic unit, whethersecondz>=600.

If the CPU 501 judges, at S22, that secondz>=600 does not hold, the CPU501 goes back to S6, continuing the processing. (Forming a part of ascanning continuation means of the same scan line.)

-   (This instance corresponds to, for example, when the static visual    target will be displayed until the time point 605 at the position    600 in FIG. 8) (Alternatively, after S12, the CPU 501 substitutes    the value of firstz at that time into a variable firstzd and stores    the result on a memory device (for example, such as a RAM 502, a HDD    504, etc.), and the CPU 501 substitutes the value of counbv at that    time into a variable counbvz and stores the result on a memory    device (for example, such as a RAM 502, a HDD 504, etc.), and,    before going back to S6 after S22, the CPU 501 reads out the values    of the variable firstzd and the variable counbvz from the memory    device (for example, such as the RAM 502, the HDD 504, etc.), and    the CPU 501 displays a visual target with the color of the    background color of the visual field scanning screen 1, and with the    size and shape set at S12, at x coordinate of firstzd dots and y    coordinate of 20+counbvz dots on the visual field scanning screen 1,    through which the static visual target may be set to be displayed,    for example, until the time point 604 at the position 600, for    example, in FIG. 8.)

If the CPU 501 judges, at S22, that secondz>=600 is satisfied, the CPU501 initializes, at S23, the value of a variable firstz at zero (forminga part of a scanning switching means to the next scan line), andincrements, at S24, the value of a variable counb by, for example, 1,which is stored on a memory device (for example, such as a RAM 502, aHDD 504, etc.), and the CPU 501 reads out the value of the counb storedon the memory device (for example, such as the RAM 502, the HDD 504,etc.), carries out a computation of 20*counb, substitutes the resultinto a variable counbv (forming a part of a visual target scan linesetting means,) (forming a part of a scanning switching means to thenext scan line), which is stored on a memory device (for example, suchas a RAM 502, a HDD 504, etc.), and then the CPU 501 goes back to S6,continuing the processing.

-   (This instance corresponds to, for example, when the static visual    target will be displayed until the time point 605 at the position    600 in FIG. 8) (Alternatively, after S12, the CPU 501 substitutes    the value of firstz at that time into a variable firstzd and stores    the result on a memory device (for example, such as a RAM 502, a HDD    504, etc.), and the CPU 501 substitutes the value of counbv at that    time into a variable counbvz and stores the result on a memory    device (for example, such as a RAM 502, a HDD 504, etc.), and,    before going back to S6 after S24, the CPU 501 reads out the values    of the variable firstzd and the variable counbvz from the memory    device (for example, such as the RAM 502, the HDD 504, etc.), and    the CPU 501 displays a visual target with the color of the    background color of the visual field scanning screen 1, and with the    size and shape set at S12, at x coordinate of firstzd dots and y    coordinate of 20+counbvz dots on the visual field scanning screen 1,    through which the static visual target may be set to be displayed,    for example, until the time point 604 at the position 600, for    example, in FIG. 8.)

1. A perimeter comprising: means for generating, on an output device, avisual field scanning screen for scanning a visual field of a subject;means for displaying and controlling a fixation image to be fixated bysaid subject, during a visual field scanning, on the visual fieldscanning screen generated by said visual field scanning screengenerating means; means for setting a visual target scan line to scan avisual target, parallel on said visual field scanning screen; means fordisplaying and scanning said visual target on said visual field scanningscreen along the visual target scan line set by said visual target scanline parallel setting means, in order to scan the visual field; means,which is included in said visual target displaying and controllingmeans, for statically displaying and controlling said visual target, fora specific time, on said visual target scan line; means for storing, ona memory device, a position of said visual target statically displayedand controlled for said specific time by said statically displaying andcontrolling means; means, which is included in said visual targetdisplaying and controlling means, for, while said static displaying andcontrolling means displays statically said visual target for saidspecific time, giving rise to another of said visual target after apredetermined moment from the start of said specific time at theposition which said static display position storing means stores, andcontinuing said kinetic scan by starting kinetic scan from said positionalong said visual target scan line until the time point specified basedon the end point of said specific time; means for, via an input device,detecting a time when said kinetic scan, started by said kinetic displayand control starting means, of said visual target has first beenperceived by the subject's visual field; means for storing, on thememory device, a position of said visual target at the time of thedetection by said detecting means; means, through said detectionposition storing means, for storing, on the memory device, a distancefrom the position of said visual target displayed and controlledstatically for said specific time by said statically displaying andcontrolling means, to the position of said visual target kineticallydisplayed and controlled at the time of the detection by said detectingmeans, as a piece of information which reflects a function of the visualfield extending from the position of said visual target displayed andcontrolled statically for said specific time by said staticallydisplaying and controlling means, to the position of said visual targetkinetically displayed and controlled at the time of the detection bysaid detecting means; and scanning continuation means for, through saidstatically displaying and controlling means, displaying and controllingsaid visual target statically on said visual target scan line at theposition of said visual target stored by said detection position storingmeans, and proceeding from said static display position storing meansonward as above, and continuing the similar scan of said visual targetscan line by iterating above procedure along said visual target scanline, in order to continue the next scan of said visual target scan lineif the time when said kinetic scan has first been perceived by thesubject's visual field is detected via the input device by saiddetecting means; wherein said specific time being determined based onfrom the time of detection, via said input device, of a time when saidkinetic scan, started by said kinetic display and control startingmeans, of said visual target has first been perceived by the subject'svisual field, to the time of detection subsequent to said time, via saidinput device, of a time when said kinetic scan, started by said kineticdisplay and control starting means, of said visual target has first beenperceived by the subject's visual field.
 2. A program for causing acomputer to realize a function comprising: means for generating, on anoutput device, a visual field scanning screen for scanning a visualfield of a subject; means for displaying and controlling a fixationimage to be fixated by said subject, during a visual field scanning, onthe visual field scanning screen generated by said visual field scanningscreen generating means; means for setting a visual target scan line toscan a visual target, parallel on said visual field scanning screen;means for displaying and scanning said visual target on said visualfield scanning screen along the visual target scan line set by saidvisual target scan line parallel setting means, in order to scan thevisual field; means, which is included in said visual target displayingand controlling means, for statically displaying and controlling saidvisual target, for a specific time, on said visual target scan line;means for storing, on a memory device, a position of said visual targetstatically displayed and controlled for said specific time by saidstatically displaying and controlling means; means, which is included insaid visual target displaying and controlling means, for, while saidstatic displaying and controlling means displays statically said visualtarget for said specific time, giving rise to another of said visualtarget after a predetermined moment from the start of said specific timeat the position which said static display position storing means stores,and continuing said kinetic scan by starting kinetic scan from saidposition along said visual target scan line until the time pointspecified based on the end point of said specific time; means for, viaan input device, detecting a time when said kinetic scan, started bysaid kinetic display and control starting means, of said visual targethas first been perceived by the subject's visual field; means forstoring, on the memory device, a position of said visual target at thetime of the detection by said detecting means; means, through saiddetection position storing means, for storing, on the memory device, adistance from the position of said visual target displayed andcontrolled statically for said specific time by said staticallydisplaying and controlling means, to the position of said visual targetkinetically displayed and controlled at the time of the detection bysaid detecting means, as a piece of information which reflects afunction of the visual field extending from the position of said visualtarget displayed and controlled statically for said specific time bysaid statically displaying and controlling means, to the position ofsaid visual target kinetically displayed and controlled at the time ofthe detection by said detecting means; and scanning continuation meansfor, through said statically displaying and controlling means,displaying and controlling said visual target statically on said visualtarget scan line at the position of said visual target stored by saiddetection position storing means, and proceeding from said staticdisplay position storing means onward as above, and continuing thesimilar scan of said visual target scan line by iterating aboveprocedure along said visual target scan line, in order to continue thenext scan of said visual target scan line if the time when said kineticscan has first been perceived by the subject's visual field is detectedvia the input device by said detecting means; wherein said specific timebeing determined based on from the time of detection, via said inputdevice, of a time when said kinetic scan, started by said kineticdisplay and control starting means, of said visual target has first beenperceived by the subject's visual field, to the time of detectionsubsequent to said time, via said input device, of a time when saidkinetic scan, started by said kinetic display and control startingmeans, of said visual target has first been perceived by the subject'svisual field.